Abstract: A site\|graph model to describe the logic structure of World Wide Web is introduced in this paper. Based on this model, the behavior pattern of user requests for home pages is discussed and thus a proxy cache system URAC （user request attentive cache） is implemented. The working principles of URAC and the issues on hit rate, cache coherence, and replacement strategy are addressed in details. Furthermore, the performance of URAC is predicted through simulation. It is concluded that URAC is a practical proxy cache system that can improve valid hit rate and reduce access delay.